SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72a42767cc42488cbede9afca8fdee30f481f7ad6ee0f997d9d1282c3fc41186' 
  AND token = 'abzHhkmWoCGJkMlzYoeeVsFYTzhjmyaYAWUpfevjEQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}